JPH0214973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting fuel increasing device for a fuel injection engine such as a diesel engine. This was proposed with the primary purpose of increasing the rotational speed to .

A second object of the present invention is to simplify the structure of the startup fuel increase device, making it small and compact.

A third object of the present invention is to achieve the above-mentioned effects while also being able to accurately set the initial pressure of the torque spring so that constant engine characteristics can be obtained at all times.

Conventionally, as a device for increasing fuel at the time of starting a fuel injection engine, a fork lever of a governor is interlocked with a rack for adjusting the fuel injection amount of a fuel injection pump, and the rack can be biased in the direction of decreasing fuel via the fork lever. At the same time, the governor spring biases the fork lever and rack in the direction of fuel increase from the minimum amount position to the rated increase limit position via the floating device, and when overloaded, the fork lever and the rack are biased in the direction of fuel increase through the floating device. The fork lever and rack are biased in the direction of fuel increase from the rated fuel increase restriction position to the maximum fuel increase restriction position by the torque spring interposed in A structure is known in which a start spring is provided to move the engine to the starting increase position.

However, with this conventional system, the engine speed stagnates after reaching, for example, 700 to 800 rpm, and it takes a relatively long time to reach the specified speed. The reality is that it is taking a long time (dotted line diagram in Figure 2).

The inventor believes that the cause of such rotational speed stagnation is the third
As shown in the dotted line diagram in the figure, when the engine starts, the increase in governor force causes the rack to be pushed back to the rated increase restriction position relatively early, and the fuel injection amount decreases ahead of the rise in rotation speed. was investigated.

Therefore, in order to eliminate the above-mentioned rotational speed stagnation, the inventor of the present invention made the start spring stronger and increased the rotational speed at which the rack is pushed back to the maximum increase position to a higher rotational speed than the rotational speed at which the rotational speed stagnation occurs. invented.

However, in this case, there is a tendency that hunting is likely to occur during idling operation of the engine.

The present invention does not involve such problems and does not cause rotational speed stagnation during the increase in rotational speed at startup.
In order to quickly complete the start, a starting reduction limiting spring is interposed between the fork lever and the floating device, and the rotational speed after the engine starts is adjusted to the starting reducing limiting position between the starting increasing position and the maximum increasing position. The first feature is that the fork lever is held down by a floating tool via the starting weight loss limiting spring until the governor force rises above a certain level and the governor force exceeds the set pressure of the starting weight loss limiting spring.

The second feature of the present invention is that the fork lever and the floating tool are designed to achieve the above-mentioned effects, to accurately set the initial pressure of the torque spring, and to be simple, small, and compact. A contact tool is supported on one side through a holder case so as to be movable toward the other side, and a torque spring that urges the contact tool to advance into the holder case and a start-up increase limit spring are concentrically arranged and This is because they were inserted in parallel.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a front view of a starting fuel increasing device for a diesel engine, and reference numeral 1 indicates a fuel injection pump;
Reference numeral 2 indicates the rack for adjusting the fuel injection amount, and reference numeral 3 indicates the governor as a whole.

The governor 3 includes a fork lever 5 and a floating lever (floating tool) 6 that are rotatably supported on a common pivot shaft 4, and the rack 2 is interlocked with the fork lever 5.

The fork lever 5 is interlocked and connected to a thruster 7 made of a governor sleeve, and is biased in the direction of fuel reduction (leftward in the figure) via the thruster 7 at the governor force where a governor weight 8 is generated as the engine rotates. Ru.

The fork lever 5 has a cylindrical holder case 9.
are arranged in series with their axes facing the floating lever 6.

A piston 10 is inserted into the holder case 9 so as to be able to move forward and backward.
It penetrates through the insertion hole 12 in the end wall on the side of the floating lever so that it can move forward and backward toward the floating lever 6.

Further, inside the holder case 9, a torque spring 14 and a starting weight loss limiting spring 15 are provided between the end wall 13 on the opposite side of the floating lever and the piston 10.
are inserted concentrically in parallel, and the piston 10 and the contact tool 11 are biased forward and backward by the weight loss limiting spring 15 or the torque spring 14 during startup.

When the engine is stopped, the fork lever 5 is moved to the starting and increasing position (solid line in Figure 1) by the start spring 16 mounted between this and the fixed part.
is displaced.

The engine starts to start and the RPM is 700~
Low rotation speeds below 800 rpm (in this example, approx.
100 rpm), the fork lever 5 and rack 2 are moved from the starting increasing position to the starting reducing limit position (first
(Figure 1 dot-dashed line diagram). The abutting tool 11 is received by the receiving portion 17 of the floating lever 6 located at the rated increase restriction position.

The starting weight loss limiting spring 15 is the torque spring 1
It has a built-in height higher than the free height of 4, and has a predetermined set pressure, that is, rotation speed stagnation has conventionally occurred.
Rotation speed exceeding 700 to 800 rpm (in this example, approximately
It is assembled into the holder case 9 at a set pressure that equally opposes the governor force at 870 rpm).

As a result, after the start of the engine, the fork lever 5 and the rack 2, which have been displaced to the start-up weight loss limiting position, are adjusted so that the engine rotational speed reaches the above-mentioned appropriate rotational speed (approx.
870 rpm) (solid line diagram in Figure 3).

By holding the fork lever 5 and the rack 2 at the start-up reduction limit position until the engine speed reaches the above-mentioned appropriate speed, the fuel injection amount of the fuel injection pump 1 is increased from the maximum amount during operation. Since the engine is kept in an increased state and the engine is operated with high torque, there is no rotation speed stagnation even in the rotation range of 700 to 800 rpm, where rotation speed stagnation occurs in the past, and the above-mentioned appropriate speed is maintained. The engine rotation speed rises to the rotation speed (solid line diagram in Figure 2).

When the engine speed increases above the appropriate speed, the starting weight reduction limiting spring 15 is compressed, and approximately
At 1000 rpm, both ends of the torque spring 14 reach the maximum increase position where they are received by the piston 10 and the end wall 13 on the anti-floating lever side of the holder case 9, and further, the torque spring 14 and the starting reduction limit spring 15 reach their maximum deflection. The increase limit position (double-dashed line in FIG. 1) is reached. The governor force rotates enough to displace the fork lever 5, the rack 2, and the floating lever 6 from the rated increase restriction position to the fuel reduction side in opposition to the governor spring 18, torque spring 14, start reduction limit spring 15, and start spring 16. (approximately 1750 rpm in this example), the fork lever 5, rack 2, and floating lever 6 are further displaced toward the fuel reduction side, and eventually reach the set rotation speed (approximately 3000 rpm) and reach the set rotation speed position. Starting is completed by positioning the engine at .

19 is a speed setting lever for setting the tension of the governor spring 18; 20 is a rated increase limiter that receives the floating lever 6 from the fuel increase side at the rated increase limit position; 21 is a contact tool connected to the rack 2; 22 is a low-speed weight loss limiting device that receives the abutting tool 21 at the minimum amount position from the fuel weight loss side.

The present invention is not limited to the above-described embodiments; for example, as shown in the following (a) to (c), a part of the configuration may deviate from the essential technical idea of the present invention. It can be transformed without any problem.

(a) Although not shown, a holder case is connected to the floating lever, and a contact tool supported by the floating lever via the holder case and piston is a part of the fork lever or a catch connected to the fork lever. It may be deformed so that it can be received at the part.

(b) The contact tool supported by the fork lever (or floating lever) may be received by the receiving part of the floating lever (or fork lever) when the engine is stopped. In this case, the starting increase position and the starting reduction limit position match.

(c) As shown in FIG. 4, the holder case 9 is formed into a double cylinder shape, and the torque spring 14 and the piston 10 are inserted into the inner cylinder 9b which is slidably fitted into the outer cylinder 9a. A starting weight loss limiting spring 15 may be inserted between the outer cylinders 9b and 9a, respectively.
In this case, by appropriately selecting the built-in pressure of the torque spring 14, it is possible to prevent the fork lever and rack from moving in the decreasing direction even at the maximum increasing position.

(d) As shown in FIG. 5, a floating slider 6 is used in place of the floating lever 6, and is slidably inserted into a slide groove 23 formed in the main body 1a of the pump 1. Then, the slider 6 is operatively connected to the fork lever 5 via the rack 2.

As mentioned above, the present invention merely adds a starting weight loss limiting spring with an appropriate set pressure between the conventional fork lever and the floating device.
After the engine starts, the fork lever and rack are held at the starting reduction limit position, which is further on the fuel increase side than the maximum increase position, until the engine speed rises below a certain level and the governor force exceeds the set pressure. The displacement of the lever in the direction of fuel reduction does not precede the rise in rotation speed, and the rotation speed does not stagnate while the rotation speed is rising, allowing the start to be completed quickly, and the structure is simple, easy, and inexpensive. Can be implemented.

Further, in the present invention, the contact tool is supported on one side of the fork lever and the floating tool through the holder case so as to be movable toward the other side, and a torque spring and a starting weight reduction limiting spring are installed in the holder case. Because they are inserted concentrically and in parallel, compared to a structure in which the torque spring and the starting weight loss limiting spring are separately supported by one or both of the fork lever and floating device via separate holder cases, Not only is the structure simple, but the dead space inside the starting weight loss limiting spring can be effectively used as storage space for the torque spring, making it compact and compact.
And it can be made compact.

Moreover, while producing the above effects, the torque spring and the start-up weight loss limiting spring are inserted concentrically and in parallel within the holder case, so the initial pressure of the torque spring matches the spring pressure of the start-up weight loss limiting spring. In addition, the initial pressure of the starting weight reduction limit spring can be set accurately regardless of the spring pressure of the torque spring, so the rotation speed will not stagnate while the rotation speed is rising. You can definitely eliminate it.

[Brief explanation of drawings]

Fig. 1 is a front view of the diesel engine starting fuel increasing device according to the present invention, Fig. 2 is a rotation speed-time relation diagram schematically showing the rotation speed rise characteristic at starting, and Fig. 3 is a starting A rack position-time relationship diagram showing the rack displacement characteristics over time. FIG. 4 is an enlarged sectional view of the main part of another embodiment, and FIG. 5 is a first diagram of another embodiment.
It is a figure equivalent figure. 1... Fuel injection pump, 2... Rack, 3...
Governor, 5... Fork lever, 6... Floating tool, 9... Holder case, 11... Contact tool, 14... Torque spring, 15... Starting weight loss limiting spring, 16... Start spring, 1
7...Reception part, 18...Governor spring.

Claims (1)

[Scope of Claims] 1. A fork lever 5 of a governor 3 is interlocked and connected to a fuel injection amount adjusting rack 2 of a fuel injection pump 1, so that the rack 2 can be biased in the direction of fuel reduction via the fork lever 5 by the governor force. In addition, the fork lever 5 is configured to be able to be biased in the direction of fuel increase from the minimum amount position to the rated increase restriction position via the floating device 6 by the governor spring 18, and the fork lever 5 is biased in the fuel increase direction during overload operation. A torque spring 14 that biases the fuel in the direction of fuel increase from the rated fuel increase restriction position to the maximum fuel increase restriction position is interposed between the fork lever 5 and the floating device 6, and the fork lever 5 is moved from the maximum fuel increase position when the engine is stopped. Furthermore, in a starting fuel increase device for a fuel injection engine that is provided with a start spring 16 that moves the starting spring 16 to a starting increasing position on the fuel increasing side, the fork lever 5, which is biased by the governor force when starting the engine, is moved from the starting increasing position to the maximum increasing position. The floating device 6 receives the amount at the starting weight loss limiting position via the starting weight loss limiting spring 15, and when the engine speed rises above a certain level after starting, the governor force moves to the starting weight loss limiting position at the starting weight loss limiting position. The fork lever 5 is configured to be held at the starting reduction limit position until the set pressure is exceeded, and a contact tool 11 is connected to one of the fork lever 5 and the floating tool 6 to the other through the holder case 9. A torque spring 14 that supports the contacting tool 11 so as to be movable in the holder case 9 and urges the contact tool 11 to move back and forth in the holder case 9 and a starting weight loss limiting spring 15 are arranged concentrically.
A fuel increasing device for starting a fuel injection engine, characterized in that the devices are inserted in parallel.